Generally, the optical disk is classified as one of a CD-I (Compact Disk Interactive Media), a photo-CD (Photo Compact Disk), a CD-ROM (Compact Disk ROM), a DVD (Digital Video Disk), and a CD-RAM. Digital data is optically recorded on each of these.
A CD-ROM typically has a label indicative of its contents. A user wishing to know the contents of a CD-ROM need only read the label. As such, it is not necessary for the user to insert the CD-ROM into the CD-ROM player device in order to know the contents of the CD-ROM. Because it is a read-only memory (ROM), the contents of the CD-ROM cannot be changed and the label will always accurately reflect its contents.
Recently, optical disks have been fabricated that can record data thereon and reproduce the thusly recorded data. In addition, in the optical disk, Disk information, namely, the content of the CD-RAM, is recorded on a recording region or table of contents (TOC) so that a user can read the content of the disk.
A CD-RAM can have its contents altered by the user. A label indicative of the contents must be updated diligently. Even so, there is no way to be sure the label accurately reflects the contents unless the CD-RAM is inserted into the corresponding read/write device and the table of contents (TOC) for the CD-RAM is read.
As shown in FIG. 1, the conventional CD-RAM optical disk 10 includes a data recording region 20 on which a data is recorded, a TOC (Table of Content) recording region 30 on which an index of a data is recorded, and a clamp region 40 formed between the TOC recording region 30 and a center hole 50 on which no data is recorded.
The operation of searching an index recorded on the CD-RAM optical disk will now be explained.
Since there is no apparatus for reading only an index, in order for a user to search the content of an index recorded in a TOC recording region, a disk must be mounted on a disk player (not shown) and then played. Thereafter, the content thereof is displayed on a monitor, so that a user can check the index displayed on the monitor.
Namely, when the disk is mounted on the disk player and then is played, an optical pick-up apparatus is driven for reading data recorded on the disk. A laser beam is radiated onto the TOC region of the disk and picks up a beam reflected from the surface of the disk, thus displaying the TOC information of the disk on the monitor.
For one CD-RAM, this TOC inspection process is not too inconvenient. For several CD-RAMs, this becomes laborious for the user. For each CD-RAM, the user must remove it from its jewel-case, open the tray of the read/write device, place the CD-RAM on the tray, close the tray, initiate a TOC read process by the read/write device, open the tray, remove the CD-RAM, and return the CD-RAM to its jewel-case. Then, the same must be done for CD-RAMs.